ENGINEERING OF SELECTIVE BIOHYDROXYLATION CATALYSTS VIA DIRECTED ENZYME EVOLUTION FOR GREEN AND SUSTAINABLE CHEMICAL PRODUCTION

Abstract

REGIO- AND ENANTIOSELECTIVE BIOHYDROXYLATION IS A USEFUL REACTION IN CHEMICAL AND PHARMACEUTICAL SYNTHESIS. HOWEVER, THE PRACTICAL APPLICATION OF MONOOXYGENASES FOR THIS REACTION IS STILL LIMITED, DUE TO ITS NARROW SUBSTRATE SCOPE AND UNSATISFIED ACTIVITY AND SELECTIVITY TOWARD A GIVEN NON-NATURAL SUBSTRATE. IN THIS THESIS, WE SUCCESSFULLY ENGINEERED P450PYR MONOOXYGENASE FROM SPHINGOMONAS SP. HXN-200 BY DIRECTED EVOLUTION FOR THE REGIO- AND ENANTIOSELECTIVE SUBTERMINAL HYDROXYLATION OF N-OCTANE AND REGIOSELECTIVE TERMINAL HYDROXYLATION OF N-BUTANOL, RESPECTIVELY. ITERATIVE SATURATION MUTAGENESIS AT THE KEY SITES SELECTED FROM SUBSTRATE-P450PYR DOCKING MODEL, COUPLED WITH NEW DEVELOPED COLORIMETRIC HIGH-THROUGHPUT SCREENING ASSAYS, LED TO THE GENERATION OF A SEXTUPLE MUTANT P450PYRSM1 THAT GAVE >99% SUBTERMINAL SELECTIVITY AND 98% (S)-ENANTIOSELECTIVITY FOR THE HYDROXYLATION OF N-OCTANE, AND TWO P450PYR MUTANTS THAT SHOWED EXCELLENT TERMINAL REGIOSELECTIVITY FOR THE HYDROXYLATION OF N-